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<pre><span class="sourceLineNo">001</span><a name="line.1"></a>
<span class="sourceLineNo">002</span>/*<a name="line.2"></a>
<span class="sourceLineNo">003</span> * Copyright (C) 2014 Archie L. Cobbs. All rights reserved.<a name="line.3"></a>
<span class="sourceLineNo">004</span> *<a name="line.4"></a>
<span class="sourceLineNo">005</span> * $Id: LevelDBKVStore.html 939 2015-05-29 01:16:17Z archie.cobbs $<a name="line.5"></a>
<span class="sourceLineNo">006</span> */<a name="line.6"></a>
<span class="sourceLineNo">007</span><a name="line.7"></a>
<span class="sourceLineNo">008</span>package org.jsimpledb.kv.leveldb;<a name="line.8"></a>
<span class="sourceLineNo">009</span><a name="line.9"></a>
<span class="sourceLineNo">010</span>import com.google.common.base.Function;<a name="line.10"></a>
<span class="sourceLineNo">011</span>import com.google.common.base.Preconditions;<a name="line.11"></a>
<span class="sourceLineNo">012</span>import com.google.common.collect.Iterables;<a name="line.12"></a>
<span class="sourceLineNo">013</span><a name="line.13"></a>
<span class="sourceLineNo">014</span>import java.io.Closeable;<a name="line.14"></a>
<span class="sourceLineNo">015</span>import java.io.IOException;<a name="line.15"></a>
<span class="sourceLineNo">016</span>import java.util.AbstractMap;<a name="line.16"></a>
<span class="sourceLineNo">017</span>import java.util.Map;<a name="line.17"></a>
<span class="sourceLineNo">018</span>import java.util.NoSuchElementException;<a name="line.18"></a>
<span class="sourceLineNo">019</span><a name="line.19"></a>
<span class="sourceLineNo">020</span>import org.iq80.leveldb.DB;<a name="line.20"></a>
<span class="sourceLineNo">021</span>import org.iq80.leveldb.DBException;<a name="line.21"></a>
<span class="sourceLineNo">022</span>import org.iq80.leveldb.DBIterator;<a name="line.22"></a>
<span class="sourceLineNo">023</span>import org.iq80.leveldb.ReadOptions;<a name="line.23"></a>
<span class="sourceLineNo">024</span>import org.iq80.leveldb.WriteBatch;<a name="line.24"></a>
<span class="sourceLineNo">025</span>import org.iq80.leveldb.WriteOptions;<a name="line.25"></a>
<span class="sourceLineNo">026</span>import org.jsimpledb.kv.AbstractKVStore;<a name="line.26"></a>
<span class="sourceLineNo">027</span>import org.jsimpledb.kv.CloseableKVStore;<a name="line.27"></a>
<span class="sourceLineNo">028</span>import org.jsimpledb.kv.KVPair;<a name="line.28"></a>
<span class="sourceLineNo">029</span>import org.jsimpledb.kv.KeyRange;<a name="line.29"></a>
<span class="sourceLineNo">030</span>import org.jsimpledb.kv.mvcc.AtomicKVStore;<a name="line.30"></a>
<span class="sourceLineNo">031</span>import org.jsimpledb.kv.mvcc.Mutations;<a name="line.31"></a>
<span class="sourceLineNo">032</span>import org.jsimpledb.util.ByteUtil;<a name="line.32"></a>
<span class="sourceLineNo">033</span>import org.jsimpledb.util.CloseableTracker;<a name="line.33"></a>
<span class="sourceLineNo">034</span>import org.slf4j.Logger;<a name="line.34"></a>
<span class="sourceLineNo">035</span>import org.slf4j.LoggerFactory;<a name="line.35"></a>
<span class="sourceLineNo">036</span><a name="line.36"></a>
<span class="sourceLineNo">037</span>/**<a name="line.37"></a>
<span class="sourceLineNo">038</span> * An {@link AtomicKVStore} view of a LevelDB database.<a name="line.38"></a>
<span class="sourceLineNo">039</span> *<a name="line.39"></a>
<span class="sourceLineNo">040</span> * &lt;p&gt;<a name="line.40"></a>
<span class="sourceLineNo">041</span> * Instances must be {@link #close}'d when no longer needed to avoid leaking resources associated with iterators.<a name="line.41"></a>
<span class="sourceLineNo">042</span> * &lt;/p&gt;<a name="line.42"></a>
<span class="sourceLineNo">043</span> */<a name="line.43"></a>
<span class="sourceLineNo">044</span>public class LevelDBKVStore extends AbstractKVStore implements AtomicKVStore, CloseableKVStore {<a name="line.44"></a>
<span class="sourceLineNo">045</span><a name="line.45"></a>
<span class="sourceLineNo">046</span>    private final Logger log = LoggerFactory.getLogger(this.getClass());<a name="line.46"></a>
<span class="sourceLineNo">047</span>    private final CloseableTracker cursorTracker = new CloseableTracker();<a name="line.47"></a>
<span class="sourceLineNo">048</span>    private final ReadOptions readOptions;<a name="line.48"></a>
<span class="sourceLineNo">049</span>    private final WriteBatch writeBatch;<a name="line.49"></a>
<span class="sourceLineNo">050</span>    private final DB db;<a name="line.50"></a>
<span class="sourceLineNo">051</span><a name="line.51"></a>
<span class="sourceLineNo">052</span>    private boolean closed;<a name="line.52"></a>
<span class="sourceLineNo">053</span><a name="line.53"></a>
<span class="sourceLineNo">054</span>// Constructors<a name="line.54"></a>
<span class="sourceLineNo">055</span><a name="line.55"></a>
<span class="sourceLineNo">056</span>    /**<a name="line.56"></a>
<span class="sourceLineNo">057</span>     * Convenience constructor. Uses default read options and no write batching.<a name="line.57"></a>
<span class="sourceLineNo">058</span>     *<a name="line.58"></a>
<span class="sourceLineNo">059</span>     * @param db database<a name="line.59"></a>
<span class="sourceLineNo">060</span>     */<a name="line.60"></a>
<span class="sourceLineNo">061</span>    public LevelDBKVStore(DB db) {<a name="line.61"></a>
<span class="sourceLineNo">062</span>        this(db, null, null);<a name="line.62"></a>
<span class="sourceLineNo">063</span>    }<a name="line.63"></a>
<span class="sourceLineNo">064</span><a name="line.64"></a>
<span class="sourceLineNo">065</span>    /**<a name="line.65"></a>
<span class="sourceLineNo">066</span>     * Constructor.<a name="line.66"></a>
<span class="sourceLineNo">067</span>     *<a name="line.67"></a>
<span class="sourceLineNo">068</span>     * @param db database<a name="line.68"></a>
<span class="sourceLineNo">069</span>     * @param readOptions read options, or null for the default<a name="line.69"></a>
<span class="sourceLineNo">070</span>     * @param writeBatch batch for write operations, or null for none<a name="line.70"></a>
<span class="sourceLineNo">071</span>     * @throws IllegalArgumentException if {@code db} is null<a name="line.71"></a>
<span class="sourceLineNo">072</span>     */<a name="line.72"></a>
<span class="sourceLineNo">073</span>    public LevelDBKVStore(DB db, ReadOptions readOptions, WriteBatch writeBatch) {<a name="line.73"></a>
<span class="sourceLineNo">074</span>        if (db == null)<a name="line.74"></a>
<span class="sourceLineNo">075</span>            throw new IllegalArgumentException("null db");<a name="line.75"></a>
<span class="sourceLineNo">076</span>        this.db = db;<a name="line.76"></a>
<span class="sourceLineNo">077</span>        this.readOptions = readOptions != null ? readOptions : new ReadOptions();<a name="line.77"></a>
<span class="sourceLineNo">078</span>        this.writeBatch = writeBatch;<a name="line.78"></a>
<span class="sourceLineNo">079</span>        if (this.log.isTraceEnabled())<a name="line.79"></a>
<span class="sourceLineNo">080</span>            this.log.trace("created " + this);<a name="line.80"></a>
<span class="sourceLineNo">081</span>    }<a name="line.81"></a>
<span class="sourceLineNo">082</span><a name="line.82"></a>
<span class="sourceLineNo">083</span>// Accessors<a name="line.83"></a>
<span class="sourceLineNo">084</span><a name="line.84"></a>
<span class="sourceLineNo">085</span>    /**<a name="line.85"></a>
<span class="sourceLineNo">086</span>     * Get the {@link DB} underlying this instance.<a name="line.86"></a>
<span class="sourceLineNo">087</span>     *<a name="line.87"></a>
<span class="sourceLineNo">088</span>     * @return underlying database<a name="line.88"></a>
<span class="sourceLineNo">089</span>     */<a name="line.89"></a>
<span class="sourceLineNo">090</span>    public DB getDB() {<a name="line.90"></a>
<span class="sourceLineNo">091</span>        return this.db;<a name="line.91"></a>
<span class="sourceLineNo">092</span>    }<a name="line.92"></a>
<span class="sourceLineNo">093</span><a name="line.93"></a>
<span class="sourceLineNo">094</span>// KVStore<a name="line.94"></a>
<span class="sourceLineNo">095</span><a name="line.95"></a>
<span class="sourceLineNo">096</span>    @Override<a name="line.96"></a>
<span class="sourceLineNo">097</span>    public synchronized byte[] get(byte[] key) {<a name="line.97"></a>
<span class="sourceLineNo">098</span>        key.getClass();<a name="line.98"></a>
<span class="sourceLineNo">099</span>        if (this.closed)<a name="line.99"></a>
<span class="sourceLineNo">100</span>            throw new IllegalStateException("the store is closed");<a name="line.100"></a>
<span class="sourceLineNo">101</span>        this.cursorTracker.poll();<a name="line.101"></a>
<span class="sourceLineNo">102</span>        return this.db.get(key, this.readOptions);<a name="line.102"></a>
<span class="sourceLineNo">103</span>    }<a name="line.103"></a>
<span class="sourceLineNo">104</span><a name="line.104"></a>
<span class="sourceLineNo">105</span>    @Override<a name="line.105"></a>
<span class="sourceLineNo">106</span>    public synchronized java.util.Iterator&lt;KVPair&gt; getRange(byte[] minKey, byte[] maxKey, boolean reverse) {<a name="line.106"></a>
<span class="sourceLineNo">107</span>        if (this.closed)<a name="line.107"></a>
<span class="sourceLineNo">108</span>            throw new IllegalStateException("the store is closed");<a name="line.108"></a>
<span class="sourceLineNo">109</span>        this.cursorTracker.poll();<a name="line.109"></a>
<span class="sourceLineNo">110</span>        return new Iterator(this.db.iterator(this.readOptions), minKey, maxKey, reverse);<a name="line.110"></a>
<span class="sourceLineNo">111</span>    }<a name="line.111"></a>
<span class="sourceLineNo">112</span><a name="line.112"></a>
<span class="sourceLineNo">113</span>    @Override<a name="line.113"></a>
<span class="sourceLineNo">114</span>    public synchronized void put(byte[] key, byte[] value) {<a name="line.114"></a>
<span class="sourceLineNo">115</span>        key.getClass();<a name="line.115"></a>
<span class="sourceLineNo">116</span>        value.getClass();<a name="line.116"></a>
<span class="sourceLineNo">117</span>        if (this.closed)<a name="line.117"></a>
<span class="sourceLineNo">118</span>            throw new IllegalStateException("the store is closed");<a name="line.118"></a>
<span class="sourceLineNo">119</span>        this.cursorTracker.poll();<a name="line.119"></a>
<span class="sourceLineNo">120</span>        if (this.writeBatch != null)<a name="line.120"></a>
<span class="sourceLineNo">121</span>            this.writeBatch.put(key, value);<a name="line.121"></a>
<span class="sourceLineNo">122</span>        else<a name="line.122"></a>
<span class="sourceLineNo">123</span>            this.db.put(key, value);<a name="line.123"></a>
<span class="sourceLineNo">124</span>    }<a name="line.124"></a>
<span class="sourceLineNo">125</span><a name="line.125"></a>
<span class="sourceLineNo">126</span>    @Override<a name="line.126"></a>
<span class="sourceLineNo">127</span>    public synchronized void remove(byte[] key) {<a name="line.127"></a>
<span class="sourceLineNo">128</span>        key.getClass();<a name="line.128"></a>
<span class="sourceLineNo">129</span>        if (this.closed)<a name="line.129"></a>
<span class="sourceLineNo">130</span>            throw new IllegalStateException("the store is closed");<a name="line.130"></a>
<span class="sourceLineNo">131</span>        this.cursorTracker.poll();<a name="line.131"></a>
<span class="sourceLineNo">132</span>        if (this.writeBatch != null)<a name="line.132"></a>
<span class="sourceLineNo">133</span>            this.writeBatch.delete(key);<a name="line.133"></a>
<span class="sourceLineNo">134</span>        else<a name="line.134"></a>
<span class="sourceLineNo">135</span>            this.db.delete(key);<a name="line.135"></a>
<span class="sourceLineNo">136</span>    }<a name="line.136"></a>
<span class="sourceLineNo">137</span><a name="line.137"></a>
<span class="sourceLineNo">138</span>// AtomicKVStore<a name="line.138"></a>
<span class="sourceLineNo">139</span><a name="line.139"></a>
<span class="sourceLineNo">140</span>    @Override<a name="line.140"></a>
<span class="sourceLineNo">141</span>    public synchronized CloseableKVStore snapshot() {<a name="line.141"></a>
<span class="sourceLineNo">142</span>        return new SnapshotLevelDBKVStore(this.db, this.readOptions.verifyChecksums());<a name="line.142"></a>
<span class="sourceLineNo">143</span>    }<a name="line.143"></a>
<span class="sourceLineNo">144</span><a name="line.144"></a>
<span class="sourceLineNo">145</span>    @Override<a name="line.145"></a>
<span class="sourceLineNo">146</span>    public synchronized void mutate(Mutations mutations, boolean sync) {<a name="line.146"></a>
<span class="sourceLineNo">147</span>        Preconditions.checkArgument(mutations != null, "null mutations");<a name="line.147"></a>
<span class="sourceLineNo">148</span><a name="line.148"></a>
<span class="sourceLineNo">149</span>        // Apply mutations in a batch<a name="line.149"></a>
<span class="sourceLineNo">150</span>        try (WriteBatch batch = this.db.createWriteBatch()) {<a name="line.150"></a>
<span class="sourceLineNo">151</span><a name="line.151"></a>
<span class="sourceLineNo">152</span>            // Apply removes<a name="line.152"></a>
<span class="sourceLineNo">153</span>            final ReadOptions iteratorOptions = new ReadOptions()<a name="line.153"></a>
<span class="sourceLineNo">154</span>              .verifyChecksums(this.readOptions.verifyChecksums())<a name="line.154"></a>
<span class="sourceLineNo">155</span>              .snapshot(this.readOptions.snapshot())<a name="line.155"></a>
<span class="sourceLineNo">156</span>              .fillCache(false);<a name="line.156"></a>
<span class="sourceLineNo">157</span>            for (KeyRange range : mutations.getRemoveRanges()) {<a name="line.157"></a>
<span class="sourceLineNo">158</span>                final byte[] min = range.getMin();<a name="line.158"></a>
<span class="sourceLineNo">159</span>                final byte[] max = range.getMax();<a name="line.159"></a>
<span class="sourceLineNo">160</span>                if (min != null &amp;&amp; max != null &amp;&amp; ByteUtil.compare(max, ByteUtil.getNextKey(min)) == 0)<a name="line.160"></a>
<span class="sourceLineNo">161</span>                    batch.delete(min);<a name="line.161"></a>
<span class="sourceLineNo">162</span>                else {<a name="line.162"></a>
<span class="sourceLineNo">163</span>                    try (Iterator i = new Iterator(this.db.iterator(iteratorOptions), min, max, false)) {<a name="line.163"></a>
<span class="sourceLineNo">164</span>                        while (i.hasNext())<a name="line.164"></a>
<span class="sourceLineNo">165</span>                            batch.delete(i.next().getKey());<a name="line.165"></a>
<span class="sourceLineNo">166</span>                    }<a name="line.166"></a>
<span class="sourceLineNo">167</span>                }<a name="line.167"></a>
<span class="sourceLineNo">168</span>            }<a name="line.168"></a>
<span class="sourceLineNo">169</span><a name="line.169"></a>
<span class="sourceLineNo">170</span>            // Apply puts<a name="line.170"></a>
<span class="sourceLineNo">171</span>            for (Map.Entry&lt;byte[], byte[]&gt; entry : mutations.getPutPairs())<a name="line.171"></a>
<span class="sourceLineNo">172</span>                batch.put(entry.getKey(), entry.getValue());<a name="line.172"></a>
<span class="sourceLineNo">173</span><a name="line.173"></a>
<span class="sourceLineNo">174</span>            // Convert counter adjustments into puts<a name="line.174"></a>
<span class="sourceLineNo">175</span>            final Function&lt;Map.Entry&lt;byte[], Long&gt;, Map.Entry&lt;byte[], byte[]&gt;&gt; counterPutFunction<a name="line.175"></a>
<span class="sourceLineNo">176</span>              = new Function&lt;Map.Entry&lt;byte[], Long&gt;, Map.Entry&lt;byte[], byte[]&gt;&gt;() {<a name="line.176"></a>
<span class="sourceLineNo">177</span>                @Override<a name="line.177"></a>
<span class="sourceLineNo">178</span>                public Map.Entry&lt;byte[], byte[]&gt; apply(Map.Entry&lt;byte[], Long&gt; adjust) {<a name="line.178"></a>
<span class="sourceLineNo">179</span><a name="line.179"></a>
<span class="sourceLineNo">180</span>                    // Decode old value<a name="line.180"></a>
<span class="sourceLineNo">181</span>                    final byte[] key = adjust.getKey();<a name="line.181"></a>
<span class="sourceLineNo">182</span>                    final long diff = adjust.getValue();<a name="line.182"></a>
<span class="sourceLineNo">183</span>                    byte[] oldBytes = LevelDBKVStore.this.db.get(key, LevelDBKVStore.this.readOptions);<a name="line.183"></a>
<span class="sourceLineNo">184</span>                    if (oldBytes == null)<a name="line.184"></a>
<span class="sourceLineNo">185</span>                        oldBytes  = new byte[8];<a name="line.185"></a>
<span class="sourceLineNo">186</span>                    final long oldValue;<a name="line.186"></a>
<span class="sourceLineNo">187</span>                    try {<a name="line.187"></a>
<span class="sourceLineNo">188</span>                        oldValue = LevelDBKVStore.this.decodeCounter(oldBytes);<a name="line.188"></a>
<span class="sourceLineNo">189</span>                    } catch (IllegalArgumentException e) {<a name="line.189"></a>
<span class="sourceLineNo">190</span>                        return null;<a name="line.190"></a>
<span class="sourceLineNo">191</span>                    }<a name="line.191"></a>
<span class="sourceLineNo">192</span><a name="line.192"></a>
<span class="sourceLineNo">193</span>                    // Add adjustment and re-encode it<a name="line.193"></a>
<span class="sourceLineNo">194</span>                    return new AbstractMap.SimpleEntry&lt;byte[], byte[]&gt;(key, LevelDBKVStore.this.encodeCounter(oldValue + diff));<a name="line.194"></a>
<span class="sourceLineNo">195</span>                }<a name="line.195"></a>
<span class="sourceLineNo">196</span>            };<a name="line.196"></a>
<span class="sourceLineNo">197</span><a name="line.197"></a>
<span class="sourceLineNo">198</span>            // Apply counter adjustments<a name="line.198"></a>
<span class="sourceLineNo">199</span>            for (Map.Entry&lt;byte[], byte[]&gt; entry : Iterables.transform(mutations.getAdjustPairs(), counterPutFunction)) {<a name="line.199"></a>
<span class="sourceLineNo">200</span>                if (entry != null)<a name="line.200"></a>
<span class="sourceLineNo">201</span>                    batch.put(entry.getKey(), entry.getValue());<a name="line.201"></a>
<span class="sourceLineNo">202</span>            }<a name="line.202"></a>
<span class="sourceLineNo">203</span><a name="line.203"></a>
<span class="sourceLineNo">204</span>            // Write the batch<a name="line.204"></a>
<span class="sourceLineNo">205</span>            this.db.write(batch, new WriteOptions().sync(sync));<a name="line.205"></a>
<span class="sourceLineNo">206</span>        } catch (IOException e) {<a name="line.206"></a>
<span class="sourceLineNo">207</span>            throw new DBException("error applying changes to LevelDB", e);<a name="line.207"></a>
<span class="sourceLineNo">208</span>        }<a name="line.208"></a>
<span class="sourceLineNo">209</span>    }<a name="line.209"></a>
<span class="sourceLineNo">210</span><a name="line.210"></a>
<span class="sourceLineNo">211</span>// Object<a name="line.211"></a>
<span class="sourceLineNo">212</span><a name="line.212"></a>
<span class="sourceLineNo">213</span>    /**<a name="line.213"></a>
<span class="sourceLineNo">214</span>     * Finalize this instance. Invokes {@link #close} to close any unclosed iterators.<a name="line.214"></a>
<span class="sourceLineNo">215</span>     */<a name="line.215"></a>
<span class="sourceLineNo">216</span>    @Override<a name="line.216"></a>
<span class="sourceLineNo">217</span>    protected void finalize() throws Throwable {<a name="line.217"></a>
<span class="sourceLineNo">218</span>        try {<a name="line.218"></a>
<span class="sourceLineNo">219</span>            if (!this.closed)<a name="line.219"></a>
<span class="sourceLineNo">220</span>               this.log.warn(this + " leaked without invoking close()");<a name="line.220"></a>
<span class="sourceLineNo">221</span>            this.close();<a name="line.221"></a>
<span class="sourceLineNo">222</span>        } finally {<a name="line.222"></a>
<span class="sourceLineNo">223</span>            super.finalize();<a name="line.223"></a>
<span class="sourceLineNo">224</span>        }<a name="line.224"></a>
<span class="sourceLineNo">225</span>    }<a name="line.225"></a>
<span class="sourceLineNo">226</span><a name="line.226"></a>
<span class="sourceLineNo">227</span>    @Override<a name="line.227"></a>
<span class="sourceLineNo">228</span>    public String toString() {<a name="line.228"></a>
<span class="sourceLineNo">229</span>        return this.getClass().getSimpleName()<a name="line.229"></a>
<span class="sourceLineNo">230</span>          + "[db=" + this.db<a name="line.230"></a>
<span class="sourceLineNo">231</span>          + ",options=" + this.readOptions<a name="line.231"></a>
<span class="sourceLineNo">232</span>          + (this.writeBatch != null ? ",writeBatch=" + this.writeBatch : "")<a name="line.232"></a>
<span class="sourceLineNo">233</span>          + "]";<a name="line.233"></a>
<span class="sourceLineNo">234</span>    }<a name="line.234"></a>
<span class="sourceLineNo">235</span><a name="line.235"></a>
<span class="sourceLineNo">236</span>// Closeable<a name="line.236"></a>
<span class="sourceLineNo">237</span><a name="line.237"></a>
<span class="sourceLineNo">238</span>    /**<a name="line.238"></a>
<span class="sourceLineNo">239</span>     * Close this instance.<a name="line.239"></a>
<span class="sourceLineNo">240</span>     *<a name="line.240"></a>
<span class="sourceLineNo">241</span>     * &lt;p&gt;<a name="line.241"></a>
<span class="sourceLineNo">242</span>     * This closes any unclosed iterators returned from {@link #getRange getRange()}.<a name="line.242"></a>
<span class="sourceLineNo">243</span>     * This does not close the underlying {@link DB} or any associated {@link WriteBatch}.<a name="line.243"></a>
<span class="sourceLineNo">244</span>     */<a name="line.244"></a>
<span class="sourceLineNo">245</span>    @Override<a name="line.245"></a>
<span class="sourceLineNo">246</span>    public synchronized void close() {<a name="line.246"></a>
<span class="sourceLineNo">247</span>        if (this.closed)<a name="line.247"></a>
<span class="sourceLineNo">248</span>            return;<a name="line.248"></a>
<span class="sourceLineNo">249</span>        this.closed = true;<a name="line.249"></a>
<span class="sourceLineNo">250</span>        if (this.log.isTraceEnabled())<a name="line.250"></a>
<span class="sourceLineNo">251</span>            this.log.trace("closing " + this);<a name="line.251"></a>
<span class="sourceLineNo">252</span>        this.cursorTracker.close();<a name="line.252"></a>
<span class="sourceLineNo">253</span>    }<a name="line.253"></a>
<span class="sourceLineNo">254</span><a name="line.254"></a>
<span class="sourceLineNo">255</span>// Iterator<a name="line.255"></a>
<span class="sourceLineNo">256</span><a name="line.256"></a>
<span class="sourceLineNo">257</span>    private final class Iterator implements java.util.Iterator&lt;KVPair&gt;, Closeable {<a name="line.257"></a>
<span class="sourceLineNo">258</span><a name="line.258"></a>
<span class="sourceLineNo">259</span>        private final DBIterator cursor;<a name="line.259"></a>
<span class="sourceLineNo">260</span>        private final byte[] minKey;<a name="line.260"></a>
<span class="sourceLineNo">261</span>        private final byte[] maxKey;<a name="line.261"></a>
<span class="sourceLineNo">262</span>        private final boolean reverse;<a name="line.262"></a>
<span class="sourceLineNo">263</span><a name="line.263"></a>
<span class="sourceLineNo">264</span>        private KVPair next;<a name="line.264"></a>
<span class="sourceLineNo">265</span>        private byte[] removeKey;<a name="line.265"></a>
<span class="sourceLineNo">266</span>        private boolean finished;<a name="line.266"></a>
<span class="sourceLineNo">267</span>        private boolean closed;<a name="line.267"></a>
<span class="sourceLineNo">268</span><a name="line.268"></a>
<span class="sourceLineNo">269</span>        Iterator(DBIterator cursor, byte[] minKey, byte[] maxKey, boolean reverse) {<a name="line.269"></a>
<span class="sourceLineNo">270</span><a name="line.270"></a>
<span class="sourceLineNo">271</span>            // Make sure we eventually close the iterator<a name="line.271"></a>
<span class="sourceLineNo">272</span>            LevelDBKVStore.this.cursorTracker.add(this, cursor);<a name="line.272"></a>
<span class="sourceLineNo">273</span><a name="line.273"></a>
<span class="sourceLineNo">274</span>            // Sanity checks<a name="line.274"></a>
<span class="sourceLineNo">275</span>            assert Thread.holdsLock(LevelDBKVStore.this);<a name="line.275"></a>
<span class="sourceLineNo">276</span>            if (minKey != null &amp;&amp; maxKey != null &amp;&amp; ByteUtil.compare(minKey, maxKey) &gt; 0)<a name="line.276"></a>
<span class="sourceLineNo">277</span>                throw new IllegalArgumentException("minKey &gt; maxKey");<a name="line.277"></a>
<span class="sourceLineNo">278</span><a name="line.278"></a>
<span class="sourceLineNo">279</span>            // Initialize<a name="line.279"></a>
<span class="sourceLineNo">280</span>            this.cursor = cursor;<a name="line.280"></a>
<span class="sourceLineNo">281</span>            this.minKey = minKey;<a name="line.281"></a>
<span class="sourceLineNo">282</span>            this.maxKey = maxKey;<a name="line.282"></a>
<span class="sourceLineNo">283</span>            this.reverse = reverse;<a name="line.283"></a>
<span class="sourceLineNo">284</span>            if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.284"></a>
<span class="sourceLineNo">285</span>                LevelDBKVStore.this.log.trace("created " + this);<a name="line.285"></a>
<span class="sourceLineNo">286</span>            if (reverse) {<a name="line.286"></a>
<span class="sourceLineNo">287</span>                if (maxKey != null) {<a name="line.287"></a>
<span class="sourceLineNo">288</span>                    if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.288"></a>
<span class="sourceLineNo">289</span>                        LevelDBKVStore.this.log.trace("seek to " + ByteUtil.toString(maxKey));<a name="line.289"></a>
<span class="sourceLineNo">290</span>                    this.cursor.seek(maxKey);<a name="line.290"></a>
<span class="sourceLineNo">291</span>                } else {<a name="line.291"></a>
<span class="sourceLineNo">292</span>                    if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.292"></a>
<span class="sourceLineNo">293</span>                        LevelDBKVStore.this.log.trace("seek to last");<a name="line.293"></a>
<span class="sourceLineNo">294</span>                    this.cursor.seekToLast();<a name="line.294"></a>
<span class="sourceLineNo">295</span>                }<a name="line.295"></a>
<span class="sourceLineNo">296</span>            } else {<a name="line.296"></a>
<span class="sourceLineNo">297</span>                if (minKey != null) {<a name="line.297"></a>
<span class="sourceLineNo">298</span>                    if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.298"></a>
<span class="sourceLineNo">299</span>                        LevelDBKVStore.this.log.trace("seek to " + ByteUtil.toString(minKey));<a name="line.299"></a>
<span class="sourceLineNo">300</span>                    this.cursor.seek(minKey);<a name="line.300"></a>
<span class="sourceLineNo">301</span>                }<a name="line.301"></a>
<span class="sourceLineNo">302</span>            }<a name="line.302"></a>
<span class="sourceLineNo">303</span><a name="line.303"></a>
<span class="sourceLineNo">304</span>            // Debug<a name="line.304"></a>
<span class="sourceLineNo">305</span>        }<a name="line.305"></a>
<span class="sourceLineNo">306</span><a name="line.306"></a>
<span class="sourceLineNo">307</span>    // Iterator<a name="line.307"></a>
<span class="sourceLineNo">308</span><a name="line.308"></a>
<span class="sourceLineNo">309</span>        @Override<a name="line.309"></a>
<span class="sourceLineNo">310</span>        public synchronized boolean hasNext() {<a name="line.310"></a>
<span class="sourceLineNo">311</span>            if (this.closed)<a name="line.311"></a>
<span class="sourceLineNo">312</span>                throw new IllegalStateException();<a name="line.312"></a>
<span class="sourceLineNo">313</span>            return this.next != null || this.findNext();<a name="line.313"></a>
<span class="sourceLineNo">314</span>        }<a name="line.314"></a>
<span class="sourceLineNo">315</span><a name="line.315"></a>
<span class="sourceLineNo">316</span>        @Override<a name="line.316"></a>
<span class="sourceLineNo">317</span>        public synchronized KVPair next() {<a name="line.317"></a>
<span class="sourceLineNo">318</span>            if (this.closed)<a name="line.318"></a>
<span class="sourceLineNo">319</span>                throw new IllegalStateException();<a name="line.319"></a>
<span class="sourceLineNo">320</span>            if (this.next == null &amp;&amp; !this.findNext())<a name="line.320"></a>
<span class="sourceLineNo">321</span>                throw new NoSuchElementException();<a name="line.321"></a>
<span class="sourceLineNo">322</span>            assert this.next != null;<a name="line.322"></a>
<span class="sourceLineNo">323</span>            final KVPair pair = this.next;<a name="line.323"></a>
<span class="sourceLineNo">324</span>            this.removeKey = pair.getKey();<a name="line.324"></a>
<span class="sourceLineNo">325</span>            this.next = null;<a name="line.325"></a>
<span class="sourceLineNo">326</span>            return pair;<a name="line.326"></a>
<span class="sourceLineNo">327</span>        }<a name="line.327"></a>
<span class="sourceLineNo">328</span><a name="line.328"></a>
<span class="sourceLineNo">329</span>        @Override<a name="line.329"></a>
<span class="sourceLineNo">330</span>        public synchronized void remove() {<a name="line.330"></a>
<span class="sourceLineNo">331</span>            if (this.closed || this.removeKey == null)<a name="line.331"></a>
<span class="sourceLineNo">332</span>                throw new IllegalStateException();<a name="line.332"></a>
<span class="sourceLineNo">333</span>            if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.333"></a>
<span class="sourceLineNo">334</span>                LevelDBKVStore.this.log.trace("remove " + ByteUtil.toString(this.removeKey));<a name="line.334"></a>
<span class="sourceLineNo">335</span>            LevelDBKVStore.this.remove(this.removeKey);<a name="line.335"></a>
<span class="sourceLineNo">336</span>            this.removeKey = null;<a name="line.336"></a>
<span class="sourceLineNo">337</span>        }<a name="line.337"></a>
<span class="sourceLineNo">338</span><a name="line.338"></a>
<span class="sourceLineNo">339</span>        private synchronized boolean findNext() {<a name="line.339"></a>
<span class="sourceLineNo">340</span><a name="line.340"></a>
<span class="sourceLineNo">341</span>            // Sanity check<a name="line.341"></a>
<span class="sourceLineNo">342</span>            assert this.next == null;<a name="line.342"></a>
<span class="sourceLineNo">343</span>            if (this.finished)<a name="line.343"></a>
<span class="sourceLineNo">344</span>                return false;<a name="line.344"></a>
<span class="sourceLineNo">345</span><a name="line.345"></a>
<span class="sourceLineNo">346</span>            // Advance LevelDB cursor<a name="line.346"></a>
<span class="sourceLineNo">347</span>            try {<a name="line.347"></a>
<span class="sourceLineNo">348</span>                this.next = new KVPair(this.reverse ? this.cursor.prev() : this.cursor.next());<a name="line.348"></a>
<span class="sourceLineNo">349</span>                if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.349"></a>
<span class="sourceLineNo">350</span>                    LevelDBKVStore.this.log.trace("seek " + (this.reverse ? "previous" : "next") + " -&gt; " + this.next);<a name="line.350"></a>
<span class="sourceLineNo">351</span>            } catch (NoSuchElementException e) {<a name="line.351"></a>
<span class="sourceLineNo">352</span>                if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.352"></a>
<span class="sourceLineNo">353</span>                    LevelDBKVStore.this.log.trace("seek " + (this.reverse ? "previous" : "next") + " -&gt; NO MORE");<a name="line.353"></a>
<span class="sourceLineNo">354</span>                this.finished = true;<a name="line.354"></a>
<span class="sourceLineNo">355</span>                return false;<a name="line.355"></a>
<span class="sourceLineNo">356</span>            }<a name="line.356"></a>
<span class="sourceLineNo">357</span><a name="line.357"></a>
<span class="sourceLineNo">358</span>            // Check limit bound<a name="line.358"></a>
<span class="sourceLineNo">359</span>            if (this.reverse ?<a name="line.359"></a>
<span class="sourceLineNo">360</span>              (this.minKey != null &amp;&amp; ByteUtil.compare(this.next.getKey(), this.minKey) &lt; 0) :<a name="line.360"></a>
<span class="sourceLineNo">361</span>              (this.maxKey != null &amp;&amp; ByteUtil.compare(this.next.getKey(), this.maxKey) &gt;= 0)) {<a name="line.361"></a>
<span class="sourceLineNo">362</span>                if (LevelDBKVStore.this.log.isTraceEnabled()) {<a name="line.362"></a>
<span class="sourceLineNo">363</span>                    LevelDBKVStore.this.log.trace("stopping at bound "<a name="line.363"></a>
<span class="sourceLineNo">364</span>                      + ByteUtil.toString(this.reverse ? this.minKey : this.maxKey));<a name="line.364"></a>
<span class="sourceLineNo">365</span>                }<a name="line.365"></a>
<span class="sourceLineNo">366</span>                this.next = null;<a name="line.366"></a>
<span class="sourceLineNo">367</span>                this.finished = true;<a name="line.367"></a>
<span class="sourceLineNo">368</span>                return false;<a name="line.368"></a>
<span class="sourceLineNo">369</span>            }<a name="line.369"></a>
<span class="sourceLineNo">370</span><a name="line.370"></a>
<span class="sourceLineNo">371</span>            // Done<a name="line.371"></a>
<span class="sourceLineNo">372</span>            return true;<a name="line.372"></a>
<span class="sourceLineNo">373</span>        }<a name="line.373"></a>
<span class="sourceLineNo">374</span><a name="line.374"></a>
<span class="sourceLineNo">375</span>    // Closeable<a name="line.375"></a>
<span class="sourceLineNo">376</span><a name="line.376"></a>
<span class="sourceLineNo">377</span>        @Override<a name="line.377"></a>
<span class="sourceLineNo">378</span>        public synchronized void close() {<a name="line.378"></a>
<span class="sourceLineNo">379</span>            if (this.closed)<a name="line.379"></a>
<span class="sourceLineNo">380</span>                return;<a name="line.380"></a>
<span class="sourceLineNo">381</span>            this.closed = true;<a name="line.381"></a>
<span class="sourceLineNo">382</span>            if (LevelDBKVStore.this.log.isTraceEnabled())<a name="line.382"></a>
<span class="sourceLineNo">383</span>                LevelDBKVStore.this.log.trace("closing " + this);<a name="line.383"></a>
<span class="sourceLineNo">384</span>            try {<a name="line.384"></a>
<span class="sourceLineNo">385</span>                this.cursor.close();<a name="line.385"></a>
<span class="sourceLineNo">386</span>            } catch (Throwable e) {<a name="line.386"></a>
<span class="sourceLineNo">387</span>                LevelDBKVStore.this.log.debug("caught exception closing db iterator (ignoring)", e);<a name="line.387"></a>
<span class="sourceLineNo">388</span>            }<a name="line.388"></a>
<span class="sourceLineNo">389</span>        }<a name="line.389"></a>
<span class="sourceLineNo">390</span><a name="line.390"></a>
<span class="sourceLineNo">391</span>    // Object<a name="line.391"></a>
<span class="sourceLineNo">392</span><a name="line.392"></a>
<span class="sourceLineNo">393</span>        @Override<a name="line.393"></a>
<span class="sourceLineNo">394</span>        public String toString() {<a name="line.394"></a>
<span class="sourceLineNo">395</span>            return LevelDBKVStore.class.getSimpleName() + "." + this.getClass().getSimpleName()<a name="line.395"></a>
<span class="sourceLineNo">396</span>              + "[minKey=" + ByteUtil.toString(this.minKey)<a name="line.396"></a>
<span class="sourceLineNo">397</span>              + ",maxKey=" + ByteUtil.toString(this.maxKey)<a name="line.397"></a>
<span class="sourceLineNo">398</span>              + (this.reverse ? ",reverse" : "")<a name="line.398"></a>
<span class="sourceLineNo">399</span>              + "]";<a name="line.399"></a>
<span class="sourceLineNo">400</span>        }<a name="line.400"></a>
<span class="sourceLineNo">401</span>    }<a name="line.401"></a>
<span class="sourceLineNo">402</span>}<a name="line.402"></a>
<span class="sourceLineNo">403</span><a name="line.403"></a>




























































</pre>
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